Technical Field
The present disclosure relates to electrosurgical apparatuses and methods for minimizing neuromuscular stimulation. More particularly, the present disclosure relates to a method and apparatus for adjusting frequencies of electrosurgical waveforms generated by an electrosurgical generator to minimize neuromuscular stimulation.
Background of Related Art
Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, thermally or non-thermally ablate, or coagulate tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency alternating current from the electrosurgical generator to the targeted tissue. A patient return electrode is placed remotely from the active electrode to conduct the current back to the generator.
In bipolar electrosurgery, return and active electrodes are placed in close proximity to each other such that an electrical circuit is formed between the two electrodes (e.g., in the case of an electrosurgical forceps). In this manner, the applied electrical current is limited to the body tissue positioned between the electrodes. Accordingly, bipolar electrosurgery generally involves the use of instruments where it is desired to achieve a focused delivery of electrosurgical energy between two electrodes positioned on the instrument, e.g. forceps or the like.
When electrosurgical energy is generated, a frequency component is included in the generated electrosurgical waveform. If a large amount of electrosurgical energy is present at a low frequency of about 100 kilo hertz (kHz) or less, the electrosurgical waveform may stimulate muscle tissue and/or nerves. Muscle and nerve stimulation may be prevented by employing neuromuscular blocking agents (NMBAs) or such stimulation may be used to identify muscles or nerves by using neuromuscular stimulation agents (NMSAs). However, use of NMSAs or NMBAs is undesirable as these agents may produce an allergic reaction and/or may result in insufficient or overly aggressive paralysis of muscles and/or nerves of a patient. Thus, there is a need for electrosurgical generators minimizing the need for NMSAs and NMBAs.